Chem help calculate the wavelength of an electromagnetic wave with a frequency of (in pic)

The following charges on individual oil droplets were obtained during an experiment similar to Millikan's. Determine a charge fo

RSB [31]

Answer:

- 1.602 x 10⁻¹⁹coulombs

Explanation:

Charge on individual oil droplet would be multiple of charge on one electron . So we will find out the minimum common factor of given individual charges that is the LCM of all the charges given.

LCM of given charges like 3.204 , 4.806 ,8.01 and 14.42 . We have neglected the power of ten( 10⁻¹⁹) because it is already a common factor to all.

The LCM is 1.602 . So charge on electron is 1.602 x 10⁻¹⁹.

4 0

3 years ago

The standard free energy of formation, ΔG∘f, of a substance is the free energy change for the formation of one mole of the subst

OLEGan [10]

Answer:

B. 2 Na(s) + O₂(g) → Na₂O₂(s); ΔG∘f=−451.0 kJ/mol

D. 2 SO(g) + O₂(g) → 2 SO₂(g); ΔG°f=−600.4 kJ/mol

Explanation:

The spontaneity of a reaction is given by the value of the standard Gibbs free energy of the reaction (ΔG°rxn). The more negative is the ΔG°rxn, the more spontaneous is a reaction.

The ΔG°rxn can be calculated using the following expression:

ΔG°rxn = ∑np × ΔG°f(products) − ∑nr × ΔG°f(reactants)

By definition, the standard Gibbs free energy of formation of simple substances in their most stable state is zero. That is why, in the reaction of formation of a compound ΔG°rxn = ΔG°f(product).

Based on the standard free energies of formation, which of the following reactions represent a feasible way to synthesize the product?

A. N₂(g) + H₂(g) → N₂H₄(g); ΔG°f=159.3 kJ/mol.

Not feasible. ΔG°rxn = ΔG°f(product) > 0.

B. 2 Na(s) + O₂(g) → Na₂O₂(s); ΔG°f=−451.0 kJ/mol

Feasible. ΔG°rxn = ΔG°f(product) < 0.

C. 2 C(s) + 2 H₂(g) → C₂H₄(g); ΔG°f=68.20 kJ/mol

Not feasible. ΔG°rxn = ΔG°f(product) > 0.

D. 2 SO(g) + O₂(g) → 2 SO₂(g); ΔG°f=−600.4 kJ/mol

Feasible. ΔG°rxn = ΔG°f(product) < 0.

3 0

3 years ago

All modern fertilizers use PO43- as a source of phosphorus. Use your knowledge of the old methods to determine the moles of phos

tamaranim1 [39]

Answer:

The answer is 0.023 moles of phosphorus

Explanation:

The 15-15-15 fertilizer is a fertilizer of great versatility, made with nitrogen, phosphorus and potassium, which makes it one of the fertilizers most used for fertilizer in the sowing plant, thus covering the crop requirements from planting. .

This fertilizer consists of 14.25% phosphorus pentoxide (P2O5). Therefore, we have to remove 14.25% at 10 grams of 15-15-15 fertilizer to calculate the moles of phosphorus. As follows:

Grams of P2O5 = 10 g x 0.1425 = 1.425 g

We calculate the molecular weight of phosphorus. We use the periodic table:

Phosphorus molecular weight = 2 x 30.97 = 61.94 g/mol

Now we calculate the moles of phosphorus in the fertilizer:

Phosphorus moles = 1,425 g/61.94 g/mol = 0.023 moles

8 0

2 years ago

In a titration, 4.7 g of an acid (HX) requires 32.6 mL of 0.54 M NaOH(aq) for complete reaction. What is the molar mass of the a

katrin2010 [14]

Answer : The molar mass of an acid is 266.985 g/mole

Explanation : Given,

Mass of an acid (HX) = 4.7 g

Volume of NaOH = 32.6 ml = 0.0326 L

Molarity of NaOH = 0.54 M = 0.54 mole/L

First we have to calculate the moles of NaOH.

$\text{Moles of }NaOH=\text{Molarity of }NaOH\times \text{Volume of solution}=0.54mole/L\times 0.0326L=0.017604mole$

Now we have to calculate the moles of an acid.

In the titration, the moles of an acid will be equal to the moles of NaOH.

Moles of an acid = Moles of NaOH = 0.017604 mole

Now we have to calculate the molar mass of and acid.

$\text{Moles of an acid}=\frac{\text{Mass of an acid}}{\text{Molar mass of an acid}}$

Now put all the given values in this formula, we get:

$0.017604mole=\frac{4.7g}{\text{Molar mass of an acid}}$

$\text{Molar mass of an acid}=266.985g/mole$

Therefore, the molar mass of an acid is 266.985 g/mole

3 0

3 years ago

Here is the electron configuration for Magnesium. How many total electrons are in the 2nd energy level?

balandron [24]

Answer:

8 electrons

Explanation:

Magnesium is present on group 2.

It has 2 valence electrons.

Electronic configuration of magnesium:

Mg₁₂ = 1s² 2s² 2p⁶ 3s²

1st energy level contain 2 electrons.(1s²)

2nd energy level contain 8 electrons. (2s² 2p⁶)

3rd energy level contain 2 electrons. (3s²)

3rs energy level of magnesium is called valence shell. It contain two valance electrons. Magnesium can easily donate its two valance electrons and get stable electronic configuration.

It react with halogens and form salt. For example,

Mg + Cl₂ → MgCl₂

7 0

2 years ago

Chem helpcalculate the wavelength of an electromagnetic wave with a frequency of (in pic)​

Chem helpcalculate the wavelength of an electromagnetic wave with a frequency of (in pic)